Polarization-sensitive vision prosthesis

Abstract

A method for controlling a vision prosthesis having an optical system in optical communication with the retina, the method including detecting a polarization state of light reflected from a retina; and at least in part on the basis of the polarization state, generating a control signal for causing a change to an optical property of the optical system.

1. A method for controlling a vision prosthesis having an optical system in optical communication with the retina, the method comprising:
 detecting a polarization state of light reflected from a retina; and 
 at least in part on the basis of the polarization state, generating a control signal for causing a change to an optical property of the optical system. 
 
   
   
     2. The method of  claim 1 , wherein generating a control signal generating the control signal at least in part on the basis of an extent to which light is reflected from a foveal region of the retina and an extent to which light is reflected from a non-foveal region of the retina. 
   
   
     3. The method of  claim 1 , wherein generating a control signal comprises generating a control signal at least in part on the basis of a polarization state associated with light reflected from a fovea of the retina. 
   
   
     4. The method of  claim 1 , further comprising causing a change to a focal length of the optical system in response to the control signal. 
   
   
     5. The method of  claim 4 , wherein causing a change to a focal length of the optical system comprises:
 changing the focal length from a first focal length to a second focal length; 
 observing a change caused by a change in the polarization state of light reflected from a retina; 
 and changing the focal length to a third focal length; 
 wherein the first focal length is between the second and third focal lengths. 
 
   
   
     6. The method of  claim 1 , wherein detecting a polarization state comprises detecting a polarization state of foveally-reflected light. 
   
   
     7. The method of  claim 1 , wherein detecting a polarization state comprises detecting a polarization state of circumfoveally-reflected light. 
   
   
     8. The method of  claim 1 , wherein detecting a polarization state comprises detecting a polarization state of a combination of foveally-reflected light and circumfoveally-reflected light. 
   
   
     9. The method of  claim 1 , wherein generating a control signal comprises generating a control signal at least in part on the basis of relative amounts of detected foveally-reflected light and circumfoveally-reflected light. 
   
   
     10. The method of  claim 1 , further comprising detecting a polarization state of light incident on the retina. 
   
   
     11. The method of  claim 10 , wherein detecting a polarization state of light incident on the retina comprises detecting a polarization state of light polarized by the cornea. 
   
   
     12. The method of  claim 10 , wherein detecting a polarization state of light incident on the retina comprises detecting the polarization state of light polarized by a polarizing filter disposed on a path between the retina and a light source. 
   
   
     13. The method of  claim 1 , further comprising causing light of a selected polarization state to be incident on the retina. 
   
   
     14. The method of  claim 13 , wherein causing light of a selected polarization state to be incident on the retina comprises placing a polarizing filter on a path between the retina and a light source. 
   
   
     15. The method of  claim 1 , further comprising comparing the polarization state of light reflected from the retina with the polarization state of light incident on the retina. 
   
   
     16. The method of  claim 15 , wherein generating a control signal comprises generating a control signal at least in part on the basis of a difference between the polarization state of light reflected from the retina and the polarization state of light incident on the retina.